Chapter Two

The atomic number of this atom (the figure) is A 6. B 4. C 10. D 12. E cannot be determined from the available information

A 6.

Which of the following is NOT a characteristic of saturated fats? A They contain at least one double bond. B They are a form of stored energy. C Their fatty acids pack tightly together. D They are usually solid at room temperature. E They are found in animals.

A They contain at least one double bond.

An unbranched polymer composed of simple sugars is A cellulose. B triglyceride. C starch. D glycogen. E glycoprotein.

A cellulose.

Decomposition reactions are commonly ________ reactions. A exothermic B endothermic C exchange D dehydration E anabolic

A exothermic

Pure water has a neutral pH because __________. A it dissociates into equal numbers of hydrogen and hydroxyl ions B it is composed of polar covalent bonds C it is composed of equal numbers of hydrogen and oxygen atoms D it is a natural buffer

A it dissociates into equal numbers of hydrogen and hydroxyl ions

Each nucleotide is composed of a(n) _____. A pentose sugar, phosphate, and nitrogenous base B adenine, thymine, guanine, uracil, and cytosine C pentose sugar and a nitrogenous base D ribose sugar, phosphate, and nitrogenous base

A pentose sugar, phosphate, and nitrogenous base

Lipids found in the cytoplasmic membranes of all eukaryotic cells are A phospholipids. B polyunsaturated fats. C waxes. D steroids. E triglycerides.

A phospholipids.

DNA is composed of repeating units of sugars, phosphates, and nucleic acids. This is an example of a A polymer. B monomer. C micelle. D lipid. E salt.

A polymer.

Which of the following is found in RNA but not DNA? A ribose B phosphate C deoxyribose D adenine E cytosine

A ribose

During the formation of a nucleic acid, such as DNA, the phosphate group of a new nucleotide covalently binds to _____ of the existing string of nucleotides. A the 3' carbon B the 5' carbon C the phosphate group D the nitrogenous base

A the 3' carbon

A stable atom has ________ in its valence shell. A 4 electrons B 8 electrons C 2 neutrons D 8 protons E 10 electrons

B 8 electrons

What is the common trait of all lipids? A They are used for energy storage. B They are at least partially hydrophobic. C They contain fatty acids. D They form bilayers.

B They are at least partially hydrophobic.

Which of the following is NOT a characteristic of phospholipids? A They are found in cellular membranes. B They contain fatty acids that associate with water. C They contain two fatty acids and a phosphate functional group. D They can form micelles and bilayers. E They contain a hydrophilic phosphate "head".

B They contain fatty acids that associate with water.

The type(s) of bond produced when atoms share electrons equally is/are A an ionic bond. B a nonpolar covalent bond. C a polar covalent bond. D a hydrogen bond. E both polar covalent and ionic bonds.

B a nonpolar covalent bond.

Which of the following is NOT a normal function of nucleotides? A building blocks of RNA B building blocks of proteins C building blocks of DNA D energy storage molecules

B building blocks of proteins Amino acids, not nucleotides, are the building blocks of proteins.

Cranberry juice has a pH of 2.4, while grape juice has a pH of 3.3; which juice has more H+ ions? A grape juice B cranberry juice C neither; these juices are both basic D cannot be determined without more information

B cranberry juice

Which of the following does not contribute significantly to the mass of an atom? A isotope B electron C element D neutron E proton

B electron

Matter composed of a single type of atom is known as a(n) A compound. B element. C mineral. D molecule. E electron.

B element.

A phosphate is moved from one molecule to another. This is an example of a/an ________ reaction. A anabolic B exchange C exothermic D endothermic E catabolic

B exchange

The reverse of a dehydration synthesis reaction is a(n) ________ reaction. A endothermic B hydrolytic C anabolic D metabolic E exchange

B hydrolytic

When the nucleus of an atom contains a constant number of protons but a variable number of neutrons, the atom is called a(n) _____. A dalton B isotope C valence D element

B isotope

Which of the following is not a type of lipid? A steroids B peptidoglycan C triglycerides D waxes

B peptidoglycan

Which of the following is found in nucleic acids? A glycerol B purines C amines D carboxylic acid E R group

B purines

An endothermic reaction __________. A exchanges energy B requires energy C releases energy D creates energy

B requires energy

The difference between ribose sugars and deoxyribose sugars is that _____. A ribose sugars are six-carbon sugars, whereas deoxyribose sugars are five-carbon sugars B ribose sugars have an extra oxygen atom C deoxyribose sugars already have a phosphate attached D ribose sugars compose purines and deoxyribose sugars compose pyrimidines

B ribose sugars have an extra oxygen atom

The high amount of energy stored within a molecule of the nucleotide adenosine triphosphate may be found _____. A within the bond between the nitrogenous base and ribose sugar B within the phosphate-phosphate bonds C within the bonds of the ribose sugar D within the bond between the nucleoside and the first phosphate

B within the phosphate-phosphate bonds (The covalent bonds between the phosphates release more energy than the sum of the two phosphates independently and are considered high-energy bonds.)

If you know that sodium chloride molecules contain ionic bonds, which of the following electronegativity values would be appropriate for the elements sodium and chlorine? A 3.0 and 4.0 B 1.0 and 1.2 C 0.9 and 3.0 D 3.0 and 2.8

C 0.9 and 3.0

All of the following are associated with ATP molecules EXCEPT A three phosphate groups. B high-energy bonds. C a long-term energy supply. D formation of coenzymes. E a recyclable energy supply.

C a long-term energy supply.

Which of the following is a bond in which electrons are shared unequally? A an ionic bond B either a polar or a nonpolar covalent bond C a polar covalent bond D a nonpolar covalent bond

C a polar covalent bond

Nucleosides differ from nucleotides in that nucleosides _____. A have a two-ring nitrogenous base B are incapable of forming bonds C are missing a phosphate D are missing a sugar

C are missing a phosphate

KH2PO4 acts as a buffer by __________. A releasing hydroxyl ions B releasing H2O C combining with hydrogen ions D combining with hydroxyl ions

C combining with hydrogen ions

The nucleotide _____ is an important signaling molecule within many cells. A adenosine B adenine C cyclic adenosine monophosphate D adenosine triphosphate

C cyclic adenosine monophosphate (Cyclic AMP is useful as a signaling molecule, but not as a major source of energy.)

Catabolism includes all of the following types of reactions EXCEPT __________. A hydrolysis reactions B exothermic reactions C dehydration synthesis reactions D decomposition reactions

C dehydration synthesis reactions

Which parts of the atoms interact in a chemical reaction? A isotopes B neutrons C electrons D ions E protons

C electrons

A synthesis reaction is also considered which of the following types of reactions? A decomposition B catabolism C endothermic D hydrolysis

C endothermic

Methane is classified as a compound because __________. A its atoms share electrons B its bonds are covalent C it contains atoms of more than one element D it has four bonds

C it contains atoms of more than one element

What type of charge does an electron have? A ions B positive C negative D neutral

C negative

All of the following are components of an amino acid EXCEPT a(n) A amino group. B α-carbon. C pentose group. D carboxyl group. E R group.

C pentose group.

A(n) ________ is a compound that dissolves into anions and cations in water. A proteins B carbohydrates C peptidoglycan D waxes E sterols

C peptidoglycan

A protein is a ________ of amino acids. A solution B bilayer C polymer D decomposition product E monomer

C polymer

In discussions of atomic mass, electrons are often ignored because __________. A they do not have an atomic mass B some atoms do not have very many electrons C their mass makes a negligible contribution to the atom's overall mass D their mass is cancelled out by the mass of the protons in the atom

C their mass makes a negligible contribution to the atom's overall mass

Mycobacterium tuberculosis is resistant to drying due to the presence of ________ in its cell wall. A sterols B peptidoglycan C waxes D proteins E carbohydrates

C waxes

Which of the following is an organic compound? A CO2 B O2 C H2O D C6H12O6 E NaCl

D C6H12O6

Which of the following is NOT true of hydrogen bonds? A The cumulative effect of many hydrogen bonds can stabilize the three-dimensional shape of large molecules B Hydrogen bonds are weak and can be broken easier than covalent of ionic bonds C They can play a role crucial role in enzyme function. D Hydrogen bonds are important only in the interaction between water molecules.

D Hydrogen bonds are important only in the interaction between water molecules. (Many of water's properties do arise from the hydrogen bonds; however, hydrogen bonds are important in many other molecules, for example DNA and protein.)

Which of the following is a property of water? A It is not a common reactant in metabolic reactions. B It is a nonpolar molecule. C It is not a good solvent. D It has a high capacity for heat. E It is liquid in a very narrow temperature range.

D It has a high capacity for heat.

The type(s) of bond produced when atoms with somewhat different electronegativities share electrons is/are A a nonpolar covalent bond. B a hydrogen bond. C an ionic bond. D a polar covalent bond. E both nonpolar covalent and ionic bonds.

D a polar covalent bond.

The valence of an atom represents its A electronegativity. B ability to attract electrons. C atomic mass. D ability to interact with other atoms. E isotopic state.

D ability to interact with other atoms

An acid dissociates in water to release A hydroxyl group(s). B hydrogen ion(s). C cation(s). D both anions and hydrogen ions. E anion(s).

D both anions and hydrogen ions.

Amino acids can combine with either hydroxyl or hydrogen ions. As a result, they can function as A solvents. B cations. C transfer groups. D buffers. E salts.

D buffers.

Which of the following are examples of pyrimidines? A thymine and adenine B cytosine and guanine C thymine and guanine D cytosine and thymine E uracil and adenine

D cytosine and thymine

A(n) ________ is an arrangement of atoms found in a variety of macromolecules and serves as their primary reactive end. A salt B buffer C isotope D functional group E stereoisomer

D functional group

The double-strands of DNA result from the formation of ________ between the bases. A peptide bonds B covalent bonds C ionic bonds D hydrogen bonds E α-1,4 bonds

D hydrogen bonds

All of the following bases are found in RNA molecules EXCEPT A uracil. B guanine. C cytosine. D thymine. E adenine.

D thymine.

Organisms use carbohydrates in all of the following ways EXCEPT A as a component of cell walls. B as a long-term energy source. C as a building block of DNA and RNA molecules. D to keep membranes flexible at low temperatures. E as a short-term energy source.

D to keep membranes flexible at low temperatures.

Which of the following is an example of a polysaccharide? A glucose B deoxyribose C fructose D sucrose E glycogen

E glycogen

Denaturation of a protein is always permanent. True/False

FALSE

Hydrogen bonds are stronger then covalent bonds. True/False

FALSE

The long-term chemical energy storage molecules in plants are steroids. True/False

FALSE

The smallest chemical units of matter are elements. True/False

FALSE

All electron shells of atoms hold eight electrons each. True/False

FASLE

A molecule composed of carbon and hydrogen is a compound. True/False

TRUE

Dehydration synthesis is a common feature of polymer production in cells. True/False

TRUE

Matter composed of a single type of atom is an element. True/False

TRUE

Salts are produced from exchange reactions in which acids and bases neutralize each other. True/False

TRUE

A(n) (catalyst/enzyme/intermediate) is any molecule that speeds up a chemical reaction.

catalyst

An atom or molecule becomes a(n) (anion/ion/cation) when it loses an electron to a more electronegative molecule.

cation

When a base dissolves in water it releases a(n) (anion/cation/hydrogen ion).

cation

Cell markers composed of both carbohydrate and lipid molecules are known as (glycoproteins/glycolipids/glycogen).

glycolipids

The DNA double helix is held together by (covalent/ionic/hydrogen) bonds.

hydrogen

A chemical reaction in which a water molecule is a reactant is known as a (dehydration/hydrolysis) reaction.

hydrolysis

Radioactive iodine is sometimes used to treat thyroid cancer. This is an example of the use of (isotopes/elements/radiation) in medical treatment.

isotopes

The (atoms/isotopes/stereoisomers) of an element vary in the number of neutrons in the nucleus.

isotopes

Steroids are (branched/multi-ringed/unbranched) hydrocarbons.

multi-ringed

A(n) (nonpolar/polar/ionic/hydrogen) bond is one in which electrons are shared equally between atoms.

nonpolar

The monomer of a nucleic acid is called a (nucleoside/nucleotide/base).

nucleotide

the figure depicts the (primary/secondary/tertiary) structure of a protein.

primary

A nitrogenous base composed of two rings is a (purine/pyrimidine/ribose).

purine

The folding of a polypeptide into a three-dimensional shape is its (secondary/tertiary/quaternary) structure.

tertiary